Codeine Substance Concentration in Serum/Plasma (24-Hour Total Mass)
This test measures the total amount of codeine, a pain reliever, in your blood over a 24-hour period. Codeine is often used to treat moderate pain and can also help with coughing.
["Your doctor may check codeine levels to monitor pain management or detect potential drug interactions."]
Key facts at a glance
- LOINC
- 27311-0
- Short code
- Codeine Free Stl-mCnt
- Synonyms
- Codeine Free Stl-mCnt
- Category
- chemistry
- Sample
- stool
- Container
- Clean container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 g
- Stability
- Refrigerated: 24h, Frozen: 7d
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you’re taking codeine for pain relief, if you have concerns about how your body processes the medication, or if you’re experiencing side effects like drowsiness, nausea, or slowed breathing. It can also help ensure the medication is working as intended or if you need adjustments to your dose.
What to Expect Before the Test
No special preparation is needed for this test. You’ll have a small needle inserted into your arm or vein to draw blood. It usually takes a few minutes, and you may feel a slight pinch. If you’re on blood thinners or have a history of bleeding issues, let your doctor know before the test.
What the Test Results Mean
The test measures the total amount of codeine in your blood over 24 hours, which includes both the drug itself and any metabolites (chemicals your body produces when breaking down codeine). High levels might indicate improper metabolism, overdose risk, or drug interactions. Low levels could suggest the medication isn’t working as expected.
Possible Side Effects or Risks
While rare, blood tests carry a small risk of bruising, pain, or infection at the injection site. If you experience excessive bleeding, swelling, or signs of infection (like redness or fever), contact your doctor immediately.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Monitoring codeine levels is important for patients with liver or kidney issues, as these organs help break down the drug. It can also help identify risks of addiction, overdose, or drug interactions with other medications (e.g., alcohol, other opioids). Doctors may use these results to adjust doses or recommend safer alternatives if needed.
Short name
Codeine Level (Total)
Frequently asked questions
How often should I get this test?
What if my results are too high?
Can I drink alcohol while taking codeine?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy